Stator for an electrical induction machine, especially a synchronous machine

ABSTRACT

A stator for an electric rotating-field induction generator that is much simpler to produce, especially regarding its windings, includes main and auxiliary poles projecting inward pressed or otherwise disposed radially onto the inner side of a yoke and positioned alternately about the circumference, of which the auxiliary poles are not wound, and the main poles are each surrounded by a coil. Each of the wound poles has a groove in the direction of the longitudinal side parallel to the axis along its longitudinal sides to accept coil sections, and these grooves include a trapezoidal cross-section and are enclosed by the non-wound auxiliary poles at the longitudinal-side groove opening. The auxiliary poles are incorporated with the yoke, and the poles are formed as separately-wound laminations that possess force-fit elements parallel to the axis on its joint sides extending toward the yoke whose force-fit elements parallel to the axis correspond to the distance to the division of the wound poles on the inner side of the yoke. The individual coils are easier to wind, and particularly may be wound directly onto the poles to be wound. The non-wound auxiliary poles isolate the coils on the wound poles from one another, and the winding heads do not come into contact with one another because the coils do not cross in the frontal area on both sides of the stator.

TECHNICAL FIELD

[0001] The invention relates to a stator for an electric rotating-fieldinduction generator, particularly for a synchronous induction machine,with at least one laminated armature stampings forming a ring-shapedyoke and a winding on its inner side that consists of several, or alarge number, of coils divided about the circumference.

BACKGROUND INFORMATION

[0002] It is accepted in rotating-field induction generators,particularly in synchronous induction machines, to position the windingsin grooves located along the inner circumferential side of the yoke.Depending on the configuration of the grooves, the individual coils ofthe overall winding basically cross and contact one another in thefrontal area. Equally complicated is the installation of the coils ofthe winding into the grooves, after which insulation from one anothermust be provided on the winding heads.

[0003] In direct-current (DC) generators, the windings are positioned onpressed poles. A stator for a DC motor that is segmented is known fromGB 2 224 399 A. The yoke of this stator is separated into individualsections that may each be connected at each end to a main pole.Interlocking force-fit elements are provided on the yoke sections and onthe main poles. Auxiliary poles may be provided between the main poleson the yoke sections by means of a dovetail connection. There is nodiscussion about the winding of the pole in GB 2 224 399 A.

[0004] Another stator for a DC motor that includes projecting main andauxiliary poles on the inner side of the yoke is known from GB 2 179 205A. The auxiliary poles may be installed onto the yoke subsequently sothat main poles that are incorporated into the stator yoke may be wound.

SUMMARY

[0005] The invention is faced with the task of producing a stator for anelectric rotating-field induction generator that is much simpler toproduce, especially regarding its windings.

[0006] For this, main and auxiliary poles projecting inward are pressedor otherwise disposed radially onto the inner side of the laminated orotherwise constructed yoke and positioned alternately about thecircumference, of which the auxiliary poles are not wound, and the mainpoles are each surrounded by a coil. Each of the wound poles has agroove in the direction of the longitudinal side parallel to the axisalong its longitudinal sides to accept coil sections, and these groovesinclude a trapezoidal cross-section and are enclosed by the non-woundauxiliary poles at the longitudinal-side groove opening. The auxiliarypoles are incorporated with the yoke, and the poles are formed asseparately-wound laminations that possess force-fit elements parallel tothe axis on its joint sides extending toward the yoke whose force-fitelements parallel to the axis correspond to the distance to the divisionof the wound poles on the inner side of the yoke.

[0007] It is one feature of the invention that the individual coils areeasier to wind, and particularly may be wound directly onto the poles tobe wound. The non-wound auxiliary poles limit the coils on the woundpoles from one another, and moreover, the winding heads do not come intocontact with one another because the coils do not cross in the frontalarea on both sides of the stator. Insulation between each of the coilsis completely unnecessary, and the individual coils themselves may thusbe more simply insulated.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] These and other features and advantages of the present inventionwill be better understood by reading the following detailed description,taken together with the drawings wherein:

[0009]FIG. 1 is a frontal view of a stator for a synchronous generatorwith a partial cutaway in the area of one of the wound poles;

[0010]FIG. 2 is a longitudinal cross-section through the stator as inFIG. 1;

[0011]FIG. 3 is an enlarged view of a partial cutaway through the statoras in FIG. 1 in the area of one of the wound poles; and

[0012]FIG. 4 is a perspective view of a pole for a stator of the typeunder discussion capable of being wound, with schematically indicatedwinding.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] In FIGS. 1 and 2, one may recognize in detail the laminatedarmature stampings of a stator for a synchronous generator with which aring-shaped yoke 1 is formed, on whose inner side main poles 2 andauxiliary poles 3 projecting inward are positioned radially. In contrastto other rotating-field induction generators that have a laminated ironcore in the stator, the illustrated stator has a main pole 2 and anauxiliary pole 3 as pressed poles.

[0014] Each of the main poles 2 bears a coil 4 that is so electricallyinterconnected with it that a rotating magnetic field results uponcurrent flow that follows the rotor (not shown).

[0015] The main poles 2 possess grooves 5 on their longitudinal sidesparallel to the axis to accept the coils 4, as FIG. 4 shows. Thesegrooves 5 lying parallel to the axis are enclosed by the auxiliary poles3 on each side of the main pole 2 that may be wound, so that a basicallytrapezoidal winding volume results to each side of each main pole 2 thatmay be wound, into which each of the two longitudinal coil sections 6 ofa coil 4 may fit. The grooves of the main poles 2 or the overall windingvolume including the flanks of the auxiliary poles 3 are covered by acoil body 9 that surrounds the coil sections accordingly.

[0016] In the frontal area of the generator, i.e., in front of the twofrontal sides of the stator, the coils 4 form somewhat semi-circularbent head sections 7, as FIG. 4 shows. For simpler winding of the mainpole 2 and formation of the head sections 7 of the coils 4, coil mounts8 are placed on the frontal side that engage with the frontal openingsof the longitudinal grooves 5 of the main pole 2, and thus may beinserted into them.

[0017] Further, one may see in FIG. 1 that there are grooves 14 parallelto the axis on the surfaces of the main pole 2 facing the air gap thatmay be present both on the main poles 2 and on the non-wound auxiliarypoles 3 that serve to preserve the symmetry of the winding consisting ofthe individual coils 4.

[0018] Winding of the main poles 2 occurs outside the stator, whichgreatly simplifies the maneuvering and installation of the coils 4.After being wound, the main poles 2, which are still separate, areinserted along the axis direction into the gap between two auxiliarypoles 3, and are inserted into the yoke 1 via the joint faces that matchthe yoke with the smallest possible air gap. For this, the yoke 1possesses force-fit elements 11 on its inner side parallel to the axisin the form of a bridge with dovetail cross-section in the separation,whose force-fit members 12 match the negative dovetail in the jointfaces 11 of the main poles 2. Additionally, longitudinal contours 13parallel to the axis may be provided on the joint faces in order toensure exact positioning of the wound main poles 2. The main poles 2represent a separately-produced lamination for the winding process thatmay also be inserted into the yoke 1 by means of force-fit elements thatare shaped differently.

[0019] Positioning of the wound main poles 2 on the yoke 1 is performedin such a manner that, when viewed from the circumferential direction ofthe yoke 1, the main poles 2 and the auxiliary poles 3 alternate withone another, i.e., an auxiliary pole 3 between two main poles 2, andvice versa, each main pole 2 is positioned between two auxiliary poles3.

[0020] Modifications and substitutions by one of ordinary skill in theart are considered to be within the scope of the present invention,which is not to be limited except by the following claims.

The invention claimed is:
 1. A stator for an electric rotating-fieldinduction generator having an armature forming a ring-shaped yoke (1)and a winding on its inner side that includes a plurality of coils (4)divided about the circumference of the ring shaped yoke, said statorcomprising: at least two main poles (2) and at least one auxiliary poles(3) projecting inward from the inner side of the ring-shaped yoke anddisposed radially onto the inner side of the laminated yoke andpositioned alternately about the circumference of the yoke, of which theat least one auxiliary poles (3) are not wound, and the at least twomain poles are each surrounded by a coil (4), each of the at least twomain poles (2) possessing a groove (5) in the direction of thelongitudinal side parallel to the axis along its longitudinal sides toaccept coil sections (6), wherein the grooves (5) include a trapezoidalcross-section and are enclosed by the non-wound auxiliary poles (3) atthe longitudinal-side groove opening, whereby the auxiliary poles (3)are incorporated with the yoke (1), and the main poles (2) are formed asseparately-wound elements that possess force-fit elements (12) parallelto the axis on its joint sides extending toward the yoke (1) whoseforce-fit elements parallel to the axis correspond to the distance tothe division of the wound poles (2) on the inner side of the yoke (1).2. A stator as in claim 1, wherein the head sections (7) of each coil(4) are positioned on the frontal openings of the grooves (5) on themain poles (2).
 3. A stator as in claim 1, wherein the grooves (5) onthe wound poles (2) are covered by the coil bodies (9) surrounding theengaged coil sections (6).
 4. A stator as in claim 1, wherein theforce-fit elements (10) of the yoke (1) and the force-fit members (12)of the wound main poles (2) possess dovetail cross-sections.
 5. A statoras in claim 1, wherein the grooves (14) parallel to the axis are presentat an air-gap side of the at least two main poles (2) and/or theauxiliary poles (3) for winding symmetry.
 6. A method for producing a ofan electrical rotating-field induction generator, particularly asynchronous generator, that includes a ring-shaped yoke and a windinglying on its inner side of the yoke that includes a plurality of coilsdistributed along the circumferential direction, said method comprisingthe acts of: providing radially-projecting alternating at least two mainpoles (2) and at least one auxiliary poles (3) disposed about thecircumference, of which the at least one auxiliary poles (3) areproduced integrated into the yoke (1) as a one-piece armature, andwherein the at least two main poles (2) are produced as a separateelement, and wherein each of the at least two main poles 2 is would witha coil (4), and wherein the at least two wound main poles (2) areinserted between the at least one auxiliary pole (3) on the inner sideof the yoke (1).
 7. The method as in claim 6, wherein the at least twowound main poles (2) are inserted into the yoke (1) by means ofinsertion parallel to the axis.